[MEDIUM:KNOWN ISSUE 6566:1.0.x]External Newsfeed unavailable bringS site down

[althoffm]

Description:
External Newsfeed unavailable will bring site down. On our website we use different newsfeeds pulled from external sites. If a website from which we pull information goes down our website get’s very slow.

Reported on:
Joomla! 1.0.9 Stable [ Sunshine ] 05 June 2006 16:00 UTC, but I have seen this happen as well on our Joombla 1.08.

Classification:
Medium.

Affected functions:
RSS newsfeeds.

Related files:
http://forum.joomla.org/index.php/topic ... #msg354592

Steps to replicate:

This is how we bring RSS newsfeeds to the frontpage.

* Component – Newsfeeds – Manage newsfeeds.- Add a feed
* Create new module fill in RSS URL, items, RSS cache standard 3600
* Create a content item only with {mosloadposition user3}, enable Frontpage.

If this feed goes down the Frontpage will get very slow. We do not use site caching, and the suggestion to disable caching on the newsfeed does not work since the component Newsfeeds does not allow the caching time to be set from 3600 to 0. I can set the RSS caching of the module to 0 but this does not work.

Analysis:
No other comments.

Proposed fix(es):.

None.

Topic / Artifact ID:
None.

System info:

PHP built On:  Windows NT net3-nl-iis-14 5.0 build 2195 
PHP Version:  5.1.4 
Web Server:  Microsoft-IIS/5.0 
Joomla! Version:  Joomla! 1.0.9 Stable [ Sunshine ] 05 June 2006 16:00 UTC

Also tested and confirmed on my test environment aka playground.

System info:
PHP built On:  …. Linux ….
PHP Version:  4.3.11 
Web Server:  Apache
Joomla! Version:  Joomla! 1.0.9 Stable [ Sunshine ] 05 June 2006 16:00 UTC

[RobS]

When I tried to duplicate this behavior with the site acting slowly, I actually encounter Internal Server Error 500 when trying to access a newsfeed that is down.  I did this by just adding a bogus entry into /etc/hosts on my server so that it would try and access a randomly chosen (not responding) IP address when attempting to get to linuxtoday.com and then tried to access the Linux Today newsfeed and received an error code 500 page. 

Perhaps it would be possible to make Joomla fail more gracefully when it cannot access an offline newsfeed. 

- Rob S.

PHP built On: FreeBSD j201.noclabs.com 6.1-RELEASE FreeBSD 6.1-RELEASE #1: Sat May 20 21:40:12 PDT 2006 [email protected]:/usr/obj/usr/src/sys/SMP i386
Database Version: 5.0.21-log
PHP Version: 5.1.4
Web Server: Apache/2.2.2 (FreeBSD) mod_fastcgi/2.4.2
WebServer to PHP interface: cgi-fcgi
Joomla! Version: Joomla! 1.0.9 Beta 3 [ Sunshine ] 21 May 2006 15:00 UTC

[user deleted]

Viewing one of the News feeds through the frontend crashes my Apache, see apache error log:
(!! It works on php 5.1.4. , probably the known issue related to newsfeeds and php 4.2.2. !!)

[Sun Jun 25 13:22:51 2006] [notice] Parent: child process exited with status 3221225477 -- Restarting.
[Sun Jun 25 13:22:51 2006] [notice] Apache/2.0.55 (Win32) PHP/4.4.2 configured -- resuming normal operations
[Sun Jun 25 13:22:51 2006] [notice] Server built: Oct  9 2005 19:16:56
[Sun Jun 25 13:22:51 2006] [notice] Parent: Created child process 3948
[Sun Jun 25 13:22:52 2006] [notice] Child 3948: Child process is running
[Sun Jun 25 13:22:52 2006] [notice] Child 3948: Acquired the start mutex.
[Sun Jun 25 13:22:52 2006] [notice] Child 3948: Starting 250 worker threads.

PHP built On:  Windows NT D1K1JG1J 5.1 build 2600
Database Version: 5.0.21-community-nt
PHP Version: 4.4.2
Web Server: Apache/2.0.55 (Win32) PHP/4.4.2
WebServer to PHP interface: apache2handler
Joomla! Version: Joomla! 1.0.10 Stable [ Sundown ] 24 June 2006 08:00 UTC
User Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.4) Gecko/20060508 Firefox/1.5.0.4

[user deleted]

Note; asked Q&T Coordinator for feedback on topic/report.

[RobS]

Q&T Note, Added to Tracker.  Artifact 6566. http://forge.joomla.org/sf/go/artf6566?nav=1

[pasamio]

There are a few issues here, one is the fact that its a 3PD module reported (I can't find a core external syndication loading module) and then there is the fact that since PHP uses non asynchronous I/O, it will block until it realizes the site is down (internal timeout from file_get_contents or in 4.3 or lower fopen) and we can't disable this because its a library call. Something like this would be good for AJAX since we're relying on an unreliable source, but it would require caching to work anyway.

I tried on a box that can't access the internet at all due to firewalling restrictions and it returned me a blank page.

[Sun Jun 25 13:22:51 2006] [notice] Parent: child process exited with status 3221225477 -- Restarting.

This appears to be an apache resource issue from the readings that I'm done and isn't directly linked to any piece of code. One comment is this:


This link is listed in a few places but doesn't exist: http://bugs.php.net/bug.php?id=26286 alternatively this one does exist: http://bugs.php.net/bug.php?id=37765 which comments that the PHP+Apache versions might not be compatible.

This link suggests that the Zend Optimizer might also cause issues: http://forums.mysql.com/read.php?52,421 ... #msg-49591

Further more perl under Windows has similar issues with Apache 2 in some cases: http://mail-archives.apache.org/mod_mbo ... e.local%3E



I would suggest that both crashes are more related to PHP and Apache inconsistencies, Windows NT based platforms seem to have the majority of the issues (http://forum.uniformserver.com/index.php?showtopic=485 same version of Apache as Robin). I would ask to see if the issue presents itself using a greater version of PHP builds (4.3 perhaps) to see if this is an issue.

[user deleted]

Thanks for the feedback Sam, I have recently upgraded so I'll have a go at this one again. I'll also try the same webserver config on a unix type machine, see if there are differences to Windows.

[pasamio]

I'm going to set this bug to pending since its in your hands at the moment.

[RobS]

I would suggest that both crashes are more related to PHP and Apache inconsistencies, Windows NT based platforms seem to have the majority of the issues (http://forum.uniformserver.com/index.php?showtopic=485 same version of Apache as Robin). I would ask to see if the issue presents itself using a greater version of PHP builds (4.3 perhaps) to see if this is an issue.

Sam, what about my report using PHP 5.1.4 (at the time) on FreeBSD?

I haven't checked the code myself yet but I suspect that it is trying to operate on the resource after opening without verifying that the open was successful.

[pasamio]

Then why crash apache? No, this is a php/apache incompatibilty issue since it isn't returning a PHP error its killing the entire operation.  Why do special combinations of versions cause the error while on different combinations the error doesn't occur using the exact same PHP code?

[pasamio]

Before I forget the actual command is file_get_contents IIRC. Which means that PHP handles everything and returns the result.

[user deleted]

Q&T Note; discussed between Robin and Rob, we agree this is not core but a php/apache issue. Closing as known issue. Out of scope to fix in 1.0.12.